How to access and manage others YouTube channel using NodeJS?

I am working on a project that helps YouTubers to access their youtube channels and update details video details. So far, I have created a youtube developer account, setup credentials and OAuth consent screen with youtube v3 API in scope.

I can successfully sign-in any user using the google sign-in button at the frontend (NextJS) and send the client id and credentials to the backend (NodeJS).

router.post("/google", function (req, res) {    try {        const { clientId, credential } = req.body;        const user = jwt.decode(credential);        console.log("clientId", clientId);        console.log("user", user);        return res.status(200).json({            message: "google",        });    } catch (error) {        console.log(error);        return res.status(500).json({            message: error.message,            data: error.data,            errCode: 500,        });    }})

Now, I want to get youtube channel details and a list of videos of the signed user so I tried this,

const oauth2Client = new OAuth2(    process.env.CLIENT_ID,    process.env.CLIENT_SECRET,    process.env.REDIRECT_URL);// get youtube channel detailsconst youtube = google.youtube({    version: "v3",    auth: oauth2Client,});youtube.channels.list({    part: "snippet",    id: user.googleId,},(err, data) => {    if (err) {        console.log("err", err);        res.status(500).send(err);    } else {        console.log("data", data);        res.status(200).send(data);    }});

But this code gives the error,

No access, refresh token, API key or refresh handler callback is set

Still, I don't under how this function will give signed youtube channels details when I am not providing any parameters to youtube API. Now, I am confused more than ever.

Can you help me figure out, how I can my app access others youtube channels? What am I missing here? 😫